We can’t help it. We assume that all faces, human or otherwise, express emotion the same way we do. That simple principle is deeply embedded in our perceptual system, and to call it anthropomorphism – the attribution of human traits to non-humans - bears a slight whiff of disapproval, as though we make a choice to see the world that way. We’re hard-wired to see anything face-like – the front of a car, the Man in the Moon, Mr. Potato Head – as alive and sentient, and we’re hard-wired to expect every face to smile and frown like humans do, whether it’s a Corolla or a crocodile. It’s likely that evolution favored humans who were prone to see faces everywhere and react accordingly. Better to be wrong and alive, then to be right and be eaten.

The subject of this month’s blog is the appearance of emotion on the face of animals. We have no problem assuming the woman in Figure 1 is either really pissed off, or excellent at pretending to be. But, I don’t have a clue what’s going on with the equally mad-looking cat in Figure 2. It’s one thing to perceive the appearance of anger in the face of an animal, but it’s another to make the leap into that creature’s brain, and come to conclusions about what they might be feeling – if anything - based on their face. Even the experts can’t really go there, and the point is, for our purposes, it doesn’t matter. All we need to know is that no one – and I mean NO ONE – can look at the cat in Figure 2 and not assume that we’re looking at one frustrated feline. It would never occur to us to wonder if the cat’s actual mood has anything to do with its face; in fact, I’m guessing that it’s totally disconnected. What’s critical here is that the similarity of the cat’s eyes and mouth to the human pose of anger makes it impossible for us to see the cat any other way than as irate. ​In last month’s blog, I talked about animators creating an almost unlimited range of expressions on the faces of stylized animals. As we know, it doesn’t stretch the audience’s credibility to have a mouse laugh or cry, as long as it’s Mickey, or for a duck to explode with anger, as long as it’s Donald (with his flexible beak.) It makes sense that, if we’re so willing to see any face as expressive, then exaggerated and reinvented animals in ​cartoons and comic strips can go just about anywhere the artist wants – and they have! Our ability to both accept and identify with cartoon animals has driven audience approval of animated features films, such as “Bambi” and “Dumbo.”

But what about realistic CG animals?

DEJECTED DOGSDo animators lose crowd buy-in if they make totally naturalistic muskrats, marmots, and moose smile and scowl in a recognizably-human way? Will the poses seem contrived and even disturbing, making us aware that it’s all trickery and mechanics (a sort of Uncanny Valley for critters)?

Let’s start by looking at some photographs I have gathered from the web with cats and dogs looking sad. ​ I then use these images of emoting animals as my point of departure for manipulating photographs of animal faces with no expression.

Figure 3 (left) One miserable dog!

​Figure 4 (above) Oblique upwards fold on a sad human eye.

Here’s a very dramatic example: the “Woe Is Me” face on the dog in Figure 3. Please keep in mind that the focus of this blog is the face only; it’s obvious that animals express themselves through posture, actions, and ear position, and this dog is doing all of the above. But body language aside, the oblique upwards fold above this German shepherd’s eyes is more than enough to make this dog look very sad, even without the cowering pose and drooping ears which are dramatic and expressive. Compare the dog’s eyes to the look of an unhappy human eye in Figure 4.

This is a very clear-cut case of an animal being able to take a human-like pose. It’s evident from a dog muscle chart just how they can accomplish this: the muscle in play is the corrugator, which they share with humans. (Incidentally, there is a theory that dogs have learned to take on this face as a way of getting the attention and sympathy of their master; it’s not hard to see why it works!)

Figure 5. One of the starring dogs from "Babe" with his default (and only) facial expression.

​The existence of the sad dog pose gives animators permission to make their realistic CG dogs sad without fear of violating their naturalness, and this visual logic can be extended to other canines, like wolves, foxes, jackals, and dingos. In fact, a lack of face movement can make CG animals appear unnecessarily static, particularly in movies where dogs, or other canines, speak and act as though they are human. Re-watching “Babe” (1995), one of the first features to include digitally-manipulated naturalistic animals, one feels that the artists are holding back too much for fear of spoiling the realistic effect. This early use of CG involved putting digital heads on real animal bodies, but the heads weren’t rigged for expressions around the eyes. An opportunity for audience empathy was thus lost; “Babe” was still a great movie, but it could have been even better.

Figure 6 (left) & Figure 7 (right) Working from the coyote photo in Figure 6, I redrew his upper lid and changed his mouth line to make it less upturned, since sad eyes make us see an almost-neutral mouth as expressing sadness, as well.

FORLORN FELINESExpressive pussy cats own the internet. There seems to be an insatiable appetite for pictures of cats with every known human expression, especially sad cats (see Figure 8). I’m not certain what mechanism reshapes the upper lid of these forlorn felines - muscle action, accident of configuration, or Photoshop? There is a “rightness” to these crazy cat images because they tap into our innate perceptual bias that animals should and do express emotions as we do, and it helps that the poses are subtle and seem organic to the structure.

Figure 8. ​Poor little kitty cats. These four miserable cats all share an oblique upper lid, which alone is enough to make them look sad. Their downturned mouths add to the effect. We don’t question the realism of the pose for a micro-moment, and we get a big kick out of the results – we empathize!

LIONS - from MAGNIFICENT to MISERABLEIt’s fair to conclude that what works for Felix will also be credible for Leo. CG artists thus have permission to manipulate the mouth and eyes of felines of all sizes without fear of striking a false note. I’ve done just that with the photo of a lion's head in Figure 9 below. The magnificent creature looks sad, pensive and thoughtful through a few tweaks of his facial features.

Figure 9 (left) Photo of a lion. Figure 10 (right) Working from the photo, I extensively reworked his upper eyelid, making it more oblique and suggesting brow crinkling above. I also enlarged his pupil to make him seem more emotive. I changed his mouth line to make it slightly downturned, an action real lions cannot do - but who's to know?

Figure 11. ​ I user-tested my manipulated lion (Figure 10), for its perceived “realism” against an excellent drawing by animal specialist Charles Knight. In spite of my invented expression, 4 out of 5 respondents thought my lion was more realistic. We are extremely forgiving when it comes to wild animals looking human, partly because we have no familiarity with how they express emotion, or what emotions they really have. A powerful bias leads us to expect their faces to look like ours.

We spend our lives observing the mobile, expressive faces of our fellow humans. When movies bring us close to animated creatures, we anticipate analogous reactions and immediately accept them as “real”. Next month I will conclude the discussion of animal expressions with a look at anger, surprise, and smiling on realistic animal faces, and talk about an anatomical coincidence that makes such poses easier to create.

I’ve done a LOT of this kind of work for films, and it’s always interesting because not all animals have the muscles needed to make those faces and quite often in realistic CG animals riggers rig according to the real muscles. What becomes most important is recognizing how we as humans see a specific facial expression and translate that into the animals anatomy

Reply

Leave a Reply.

So many faces. So many ways to express emotions. Faigin examines facial expressions in movie stills, cartoons, fine art, illustrations and photographs and shares his insightful analyses in his monthly blog.

​SUBSCRIBE: To receive an email notice of new Faigin Face Blog posts, please use the on-line Contact Form.